Detailed Predictions for: Weaver Bally
Launch Altitude (f): 6900
LZ Altitude (f): 1480
Sounding

Station:

KOAK

Date/Time:

25 AUG 2019

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
5 AM Sun 59 59 N 3 5056 6900 0 Blue 0
6 AM Sun 60 60 N 3 5056 6900 0 Blue 0
7 AM Sun 61 61 N 3 5056 6900 0 Blue 0
8 AM Sun 63 63 E 2 5056 6900 0 Blue 0
9 AM Sun 65 66 E 2 5056 6900 0 Blue 0
10 AM Sun 67 70 E 2 5543 6900 0 Blue 0
11 AM Sun 70 75 S 6 7328 6900 0 Blue 3
12 Noon Sun 73 79 S 6 8718 7433 533 Blue 6
1 PM Sun 76 83 S 6 9704 8903 2003 Blue 10
2 PM Sun 78 85 SW 8 10655 9410 2510 Blue 12
3 PM Sun 80 86 SW 8 10801 9668 2768 Blue 13
4 PM Sun 81 85 SW 8 10655 9410 2510 Blue 12
5 PM Sun 81 83 W 9 9704 8903 2003 Blue 10
6 PM Sun 80 81 W 9 9181 8488 1588 Blue 8
7 PM Sun 78 78 W 9 8509 7322 422 Blue 5
8 PM Sun 76 76 NW 5 7440 6900 0 Blue 4
9 PM Sun 73 73 NW 5 6845 6900 0 Blue 1
10 PM Sun 71 71 NW 5 6021 6900 0 Blue 0
11 PM Sun 68 68 N 3 5056 6900 0 Blue 0
12 Midnight Mon 66 66 N 3 5056 6900 0 Blue 0
1 AM Mon 64 64 N 3 5056 6900 0 Blue 0
2 AM Mon 62 62 NE 5 5056 6900 0 Blue 0
3 AM Mon 61 61 NE 5 5056 6900 0 Blue 0
4 AM Mon 61 61 NE 5 5056 6900 0 Blue 0
5 AM Mon 61 61 NE 6 5056 6900 0 Blue 0
6 AM Mon 62 62 NE 6 5056 6900 0 Blue 0
7 AM Mon 63 63 NE 6 5056 6900 0 Blue 0
8 AM Mon 65 65 E 5 5056 6900 0 Blue 0
9 AM Mon 67 68 E 5 5056 6900 0 Blue 0
10 AM Mon 70 73 E 5 6845 6900 0 Blue 1
11 AM Mon 73 78 SE 6 8509 7322 422 Blue 5
12 Noon Mon 75 81 SE 6 9181 8488 1588 Blue 8
1 PM Mon 78 85 SE 6 10655 9410 2510 Blue 12
2 PM Mon 81 88 S 6 11092 10631 3731 Blue 15
3 PM Mon 82 88 S 6 11092 10631 3731 Blue 15
4 PM Mon 84 88 S 6 11092 10631 3731 Blue 15
5 PM Mon 84 86 SW 6 10801 9668 2768 Blue 13
6 PM Mon 83 84 SW 6 9963 9150 2250 Blue 11
7 PM Mon 82 82 SW 6 9443 8696 1796 Blue 9
8 PM Mon 79 79 SW 6 8718 7433 533 Blue 6
9 PM Mon 77 77 SW 6 7552 7105 205 Blue 5
10 PM Mon 74 74 SW 6 7120 6900 0 Blue 2
11 PM Mon 71 71 N 5 6021 6900 0 Blue 0
12 Midnight Tue 68 68 N 5 5056 6900 0 Blue 0
1 AM Tue 66 66 N 5 5056 6900 0 Blue 0
2 AM Tue 65 65 N 5 5056 6900 0 Blue 0
3 AM Tue 63 63 N 5 5056 6900 0 Blue 0
4 AM Tue 63 63 N 5 5056 6900 0 Blue 0
5 AM Tue 63 63 NE 5 5056 6900 0 Blue 0
6 AM Tue 64 64 NE 5 5056 6900 0 Blue 0
7 AM Tue 66 66 NE 5 5056 6900 0 Blue 0
8 AM Tue 68 68 NE 5 5056 6900 0 Blue 0
9 AM Tue 70 71 NE 5 6021 6900 0 Blue 0
10 AM Tue 73 76 NE 5 7440 6900 0 Blue 4
11 AM Tue 76 81 SE 7 9181 8488 1588 Blue 8
12 Noon Tue 78 84 SE 7 9963 9150 2250 Blue 11
1 PM Tue 80 87 SE 7 10946 9925 3025 Blue 14
2 PM Tue 82 88 SE 7 11092 10631 3731 Blue 15
3 PM Tue 83 89 SE 7 11238 10776 3876 Blue 16
4 PM Tue 84 88 SE 7 11092 10631 3731 Blue 15
5 PM Tue 84 86 SW 6 10801 9668 2768 Blue 13
6 PM Tue 83 84 SW 6 9963 9150 2250 Blue 11
7 PM Tue 81 81 SW 6 9181 8488 1588 Blue 8
8 PM Tue 78 78 SW 6 8509 7322 422 Blue 5
9 PM Tue 75 75 SW 6 7328 6900 0 Blue 3
10 PM Tue 72 72 SW 6 6490 6900 0 Blue 0
11 PM Tue 70 70 NE 5 5543 6900 0 Blue 0
12 Midnight Wed 67 67 NE 5 5056 6900 0 Blue 0
1 AM Wed 66 66 NE 5 5056 6900 0 Blue 0
2 AM Wed 64 64 NE 5 5056 6900 0 Blue 0
3 AM Wed 63 63 NE 5 5056 6900 0 Blue 0
4 AM Wed 63 63 NE 5 5056 6900 0 Blue 0
5 AM Wed 63 63 E 6 5056 6900 0 Blue 0
6 AM Wed 64 64 E 6 5056 6900 0 Blue 0
7 AM Wed 66 66 E 6 5056 6900 0 Blue 0
8 AM Wed 68 68 E 6 5056 6900 0 Blue 0
9 AM Wed 71 72 E 6 6490 6900 0 Blue 0
10 AM Wed 73 75 E 6 7328 6900 0 Blue 3
11 AM Wed 76 79 S 8 8718 7433 533 Blue 6
12 Noon Wed 78 82 S 8 9443 8696 1796 Blue 9
1 PM Wed 80 85 S 8 10655 9410 2510 Blue 12
2 PM Wed 82 87 S 8 10946 9925 3025 Blue 14
3 PM Wed 83 87 S 8 10946 9925 3025 Blue 14
4 PM Wed 83 86 S 8 10801 9668 2768 Blue 13
5 PM Wed 83 85 SW 9 10655 9410 2510 Blue 12
6 PM Wed 81 82 SW 9 9443 8696 1796 Blue 9
7 PM Wed 79 79 SW 9 8718 7433 533 Blue 6
8 PM Wed 77 77 SW 9 7552 7105 205 Blue 5
9 PM Wed 74 74 SW 9 7120 6900 0 Blue 2
10 PM Wed 72 72 SW 9 6490 6900 0 Blue 0
11 PM Wed 69 69 SW 6 5056 6900 0 Blue 0
12 Midnight Thu 67 67 SW 6 5056 6900 0 Blue 0
1 AM Thu 65 65 SW 6 5056 6900 0 Blue 0
2 AM Thu 64 64 SW 6 5056 6900 0 Blue 0
3 AM Thu 63 63 SW 6 5056 6900 0 Blue 0
4 AM Thu 63 63 SW 6 5056 6900 0 Blue 0
5 AM Thu 63 63 E 1 5056 6900 0 Blue 0
6 AM Thu 64 64 E 1 5056 6900 0 Blue 0
7 AM Thu 65 65 E 1 5056 6900 0 Blue 0
8 AM Thu 67 67 E 1 5056 6900 0 Blue 0
9 AM Thu 69 70 E 1 5543 6900 0 Blue 0
10 AM Thu 71 74 E 1 7120 6900 0 Blue 2
11 AM Thu 73 77 S 8 7552 7105 205 Blue 5
12 Noon Thu 75 81 S 8 9181 8488 1588 Blue 8
1 PM Thu 76 82 S 8 9443 8696 1796 Blue 9
2 PM Thu 78 84 S 8 9963 9150 2250 Blue 11
3 PM Thu 79 84 S 8 9963 9150 2250 Blue 11
4 PM Thu 79 83 S 8 9704 8903 2003 Blue 10
5 PM Thu 79 81 SW 9 9181 8488 1588 Blue 8
6 PM Thu 78 79 SW 9 8718 7433 533 Blue 6
7 PM Thu 76 76 SW 9 7440 6900 0 Blue 4
8 PM Thu 74 74 SW 9 7120 6900 0 Blue 2
9 PM Thu 72 72 SW 9 6490 6900 0 Blue 0
10 PM Thu 70 70 SW 9 5543 6900 0 Blue 0
11 PM Thu 68 68 W 5 5056 6900 0 Blue 0
12 Midnight Fri 66 66 W 5 5056 6900 0 Blue 0
1 AM Fri 64 64 W 5 5056 6900 0 Blue 0
2 AM Fri 63 63 W 5 5056 6900 0 Blue 0
3 AM Fri 62 62 W 5 5056 6900 0 Blue 0
4 AM Fri 61 61 W 5 5056 6900 0 Blue 0
5 AM Fri 61 61 E 3 5056 6900 0 Blue 0
6 AM Fri 62 62 E 3 5056 6900 0 Blue 0
7 AM Fri 63 63 E 3 5056 6900 0 Blue 0
8 AM Fri 64 64 E 3 5056 6900 0 Blue 0
9 AM Fri 66 67 E 3 5056 6900 0 Blue 0
10 AM Fri 67 70 E 3 5543 6900 0 Blue 0
11 AM Fri 69 74 S 8 7120 6900 0 Blue 2
12 Noon Fri 72 78 S 8 8509 7322 422 Blue 5
1 PM Fri 73 80 S 8 8927 7545 645 Blue 7
2 PM Fri 75 81 S 8 9181 8488 1588 Blue 8
3 PM Fri 76 81 S 8 9181 8488 1588 Blue 8
4 PM Fri 77 81 S 8 9181 8488 1588 Blue 8
5 PM Fri 77 79 W 9 8718 7433 533 Blue 6
6 PM Fri 76 77 W 9 7552 7105 205 Blue 5
7 PM Fri 75 75 W 9 7328 6900 0 Blue 3
8 PM Fri 72 72 W 9 6490 6900 0 Blue 0
9 PM Fri 70 70 W 9 5543 6900 0 Blue 0
10 PM Fri 68 68 W 9 5056 6900 0 Blue 0
11 PM Fri 65 65 NW 5 5056 6900 0 Blue 0
12 Midnight Sat 63 63 NW 5 5056 6900 0 Blue 0
1 AM Sat 62 62 NW 5 5056 6900 0 Blue 0
2 AM Sat 60 60 NW 5 5056 6900 0 Blue 0
3 AM Sat 59 59 NW 5 5056 6900 0 Blue 0
4 AM Sat 59 59 NW 5 5056 6900 0 Blue 0

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse ac_soaring@yahoo.com